Cement-kiln.



T. A. EDISON.

CEMENT KILN.

APPLIGATION FILED MAB. s. 1907.

939,8 1 7. l Patented Nov. 9, 1909 THOMAS A. EDISON, OF LLEWELLYN PARK, ORANGE, NEW JERSEY.

CEMENT-KILN.

Specification of Letters Patent.

Patented Nov. 9, 1909.

Application filed March 8, 1907. Serial No. 361,415.

To all lwhom it may concern:

Be it known that I,/THoMAs ALvAEDIsoN, l a citizen of the United States, residing at Llewellyn Park, Orange, in the county of Essex and State of New Jersey, have,in vented certain newl and useful Improvements in Cement-Kilns, of which the following is a-description.

My invention'relates to improvements in rotary cement kilns of the type burning powdered fuel and my object is to provide a kiln for the purpose in which very large amounts of material may be successfully burned.

In order to increase the output of clinker in a cement kiln, it is necessary to augment the quantity of fuel burned or to direct the flame upon the walls at a sharper angle than is now practiced, but to adopt either of these expedients would be objectionable under existing conditions as it would. tend to burn out the kiln lining'. l

My improved kiln is substantially watercooled at its hottest part so that it compares favorably with the blast furnace, permits very much greaterquantities of fuel to be effectively burned, and the lining is in a measure self-regenerating like the lining of a blast furnace.

Broadly stated the invention comprises a rotary kiln in combination with ldevlces for spraying water upon the outside of its lower portion where the heat is greatest, and one or more shields ysurrounding the cooled or- 35 tion of the kiln so as to prevent the dissipation of steam within the kiln room. Preferably, the lower portion of the kiln, where the cooling effect takes place, is formed with one or more sections of cast-steel so as to effectively withstand the great differences of In order that the invention may be better understood, attention is directed to the accompanying drawing forming part of this specification, and in which Figure l is a side elevation, partly in section, through the lower portion of the kiln, equipped with my improvements in their preferred form, and 2 is a section on line 2 2 of Fig. l. In these views similar parts are represented by the same numerals of reference.

The kiln l is a long tubular structure as heretofore, maintainedat a slight angle from the horizontal, mounted on supporting rollers 2 2, driven by suitable mechanism (not stationary chamber 3, provided-with a nozzle 4 for the injection of powdered fuel, and having a lining 5 of fire brick or similar refractory material. -For its greater part. the kiln is preferably formed of cast-iron sections buttwo of the sections, (3 and 7, shown in Fig. l, within the clinkering zone, are formed preferably of cast-steel. All the sections are provided with flanges 8 8, by which the sections are bolted together and which form tracks for the supporting wheels 2. The sections 6 and 7 are each formed with two flanges 9 9, preferably cast thcre on, and engaging the outside of these flanges are the flanges 10 of a casing 11 made of sheet metal. The joints betweenA the flanges 9 and 10 fit as closely as practicable, say within a fraction of an inch, but exact tightness is not necessary, since as will be explained, a. circulation of air is maintained inwardly through the joints from the outer atmosphere to the space between the casing 11 and the kiln itself.

Located within the casing 11 are perfof rated tubes 12-12, forming spraying devices which connect with the water supply pipe 13, having controlling valves 14 14 as shown. By means of these sprayin ldevices a large quantity of water may a waysV be distributed over the sections 6 and 7 of the kiln (which correspond with the hottest part thereof) and will ow 0H' through an ordinary trap 15. The amount of water furnished to the kiln is preferably suiiiciently great as to prevent the temperature of the water from rising materially above 175o Fahr., so that it may be used for feed water purposes with important economies. Connectedwiththe casingllis an eXhauster or fan 16, maintaining circulation therein and drawing air, as explained, from the atmosphere into the casing through the joints formed between the flanges 9 and 10. By means of this exhauster any steam which may be generated within the casing will be carried off so as not to be distributed into the atmosphere, as would otherwise be the case. Byapplying large quantities of water to the outside of the kiln, as'explained, in the form v of spray, the kiln will be effectively watercooled, and the temperature of the kiln walls will be kept low enou h to prevent the lining from being burne out, even if the flame be sharply nnpinged thereon. In fact, the construction is practically as eishown), opening at its lower end within a V i cient as that of a modern blast furnace, and( the lining is protected in practically the same way, since, although up to a certain point, the lining may be disintegrated by the heat,

chemical action and mechanical attrition,

yet, when that-point is reached, its temperatre will be low enough to permit a layer of the viscous mater1al to congeal thereon and form a protective coating,

which will very materially resist disintegrat-ion.' When this protective coating 1s,

in turn, worn out,-it tends to bev again rey a stationary casing surrounding the kiln at one or more of said sections and having inwardly extending flangesv cooperating with a loose tit with the kiln -iianges, means lo# cated within the casing for spra ing water upon the kiln, and means for lea ing off the water, substantially as described.

2. In'cement burning apparatus, the combination with a rotary cement kiln formed of sections and having outwardly extendin flanges near the ends of certain sections, o a stationary casing surrounding the kiln at one or morel of said sections and having inwardly extending flanges coperating with a loose t with the ki n flanges,

passage of air through the flanged Joints into said casing, and means for leading oi water, air and steam from saidcasing, substantially as described.

.3. In cement burning apparatus, the combinationwith a rotary cement kiln formed with ianges, a casing'surrounding the kiln and having anges'coperating with those of the kiln, spraying 'devices locatedv within the casing for spraying water upon the kiln, and an exhauster orI fan connected with the casing, substantially as and for the pur poses set forth.

4. In cement bination with a rotary cement kiln formed with ianges, a casing surrounding the kiln and having flanges coperating with those of the kiln, spraying devices located within the casing for spraying water upon the kiln, and a Itrap connected with the ower end of the casing for carrying off water therefrom, substantially as and for the purposes set forth.

This specification signed and witnessed this 8th day of February 1907.

K THOS. A. EDISON.-

Witnesses:

FRANK L. DYER, FRANK D. LEWIS.

means lo-v A y cated within the casing for sprayingwater uponthe kiln, and means for caus burning apparatus, the coml 

